Amazon 10-Pack for $2.98 (matching Officeworks for $2.98, Target for $3)
Amazon 20-Pack for $4 (Officeworks has 18-pack for $3.98, Target for $4)
Amazon 36-Pack for $8 (Officeworks and Target both have 30-pack for $8)
Target also has a 48-pack for $10
Other packs available but not decent prices comparitively.
And in case you need pencils:
Faber-Castell Classic Colour Pencil 24 Pack with Sharpener 70% off $4.25
Faber-Castell Classic Colour Pencil, 12 Pack and 1 Gold Pencil 57% off $2.80
Thanks OP, how many packs required to make a bazooka?